1. Field of the Invention
The invention relates to a lock for a motor vehicle closure member such as a motor vehicle door, hood or trunk or tailgate lid. More specifically, the invention is directed to such a lock that is provided with a locking catch (latch member) that can be shifted from a latched position to an unlatched position, and a locking pin (striker) that engages the locking catch and is mounted on a support plate (striker plate) at a position that is eccentrically offset from the axis of rotation of the support plate, a solenoid motor being provided for rotating the support plate between a preliminary locking position (partially open position) and a main locking position (fully closed position).
2. Description of Related Art
The known motor vehicle lock of the initially-mentioned type, upon which the present invention is based (U.S. Pat. No. 4,775,178 to Boyko), is suitable as a door lock, hood lock or trunk lid lock for motor vehicles, and in the example disclosed in the noted patent, is used as a door lock for a sliding door of a van-type vehicle. Power motor vehicle locks, i.e., locks that are operated by a solenoid motor, are also especially important for hoods and hinged lids, for example, for trunk lids and station wagon tailgates, because of the forces necessary there.
While in other known motor vehicle door locks the locking catch, in most cases a forked rotary latch member is moved from the preliminary locking position into the main locking position in a motor-assisted manner (also reversed for a power-assisted opening), in the Boyko motor vehicle lock, from which the invention starts, the movement of the two body parts against one another, between the preliminary locking position and main locking position, is brought about by eccentric displacement of the locking pin around the axis of rotation of the support plate. Thus, in the Boyko design, the locking catch is held only in the main locking position, and to bring the position of the locking catch, including the locking pin and related lock mechanism, from the preliminary locking position into the main locking position, the locking pin must be eccentrically rotated. However, the eccentricity of the locking pin relative to the axis of rotation depends on the desired path between preliminary locking position and main locking position, and a sizeable eccentricity has the drawback that the locking pin performs a relatively great lateral relative movement in the mouth of the locking catch, to which the mouth of the locking catch has to be matched.
Also in the Boyko motor vehicle lock, various switches are provided for detecting different positions of locking pin via an actuating arm and control elements associated therewith. When opening the door lock, the locking pin is detached from the locking catch by pulling on an opening lever to release the locking catch, so that it can return to the open position, opening the door. Here, the locking pin follows the movement of the door, which opens under the action of the return spring power of the door sealing element. Simultaneously with disengagement of the locking pin and return of the locking catch into the opening position, a switch is actuated, which triggers the untwisting of the locking pin from the main locking position into the preliminary locking position by the auxiliary motor.
The Boyko motor vehicle lock has to be opened manually. It might be possible to hit on the idea to open this motor vehicle lock also by power, for example, if it is produced as a motor vehicle hood lock or a motor vehicle hinged-lid lock. For this purpose, an additional actuation mechanism for the opening lever would, then, have to be provided, for example, by a solenoid. But, this entails considerable technical expense.
While an arrangement for having the solenoid motor operate the locking catch and locking pin when opening is known (German Offenlegungsschrift 37 08 095, in which a free-wheel connection is provided), it is not feasible to apply this technique to the Boyko vehicle lock, on which this invention is based. This is because of the location of the solenoid motor and locking parts on opposed body parts in this known approach.